• DOI:10.1021/acs.nanolett.7b01924
• Corpus ID: 206741686

Terahertz Nanofocusing with Cantilevered Terahertz-Resonant Antenna Tips.

@article{Mastel2017TerahertzNW,
  title={Terahertz Nanofocusing with Cantilevered Terahertz-Resonant Antenna Tips.},
  author={Stefan Mastel and Mark B. Lundeberg and Pablo Alonso-Gonz{\'a}lez and Yuanda Gao and Kenji Watanabe and Takashi Taniguchi and James C. Hone and Frank H. L. Koppens and Alexey Yu Nikitin and Rainer Hillenbrand},
  journal={Nano letters},
  year={2017},
  volume={17 11},
  pages={
          6526-6533
        }
}

• S. Mastel, M. Lundeberg, +7 authors R. Hillenbrand
• Published 30 October 2017
• Physics
• Nano letters

We developed THz-resonant scanning probe tips, yielding strongly enhanced and nanoscale confined THz near fields at their tip apex. The tips with length in the order of the THz wavelength (λ = 96.5 μm) were fabricated by focused ion beam (FIB) machining and attached to standard atomic force microscopy (AFM) cantilevers. Measurements of the near-field intensity at the very tip apex (25 nm radius) as a function of tip length, via graphene-based (thermoelectric) near-field detection, indicate their first and second order geometrical antenna resonances for tip length of 33 and 78 μm, respectively. On resonance, we find that the near-field intensity is enhanced by one order of magnitude compared to tips of 17 μm length (standard AFM tip length), which is corroborated by numerical simulations that further predict remarkable intensity enhancements of about 107 relative to the incident field. Because of the strong field enhancement and standard AFM operation of our tips, we envision manifold and straightforward future application in scattering-type THz near-field nanoscopy and THz photocurrent nanoimaging, nanoscale nonlinear THz imaging, or nanoscale control and manipulation of matter employing ultrastrong and ultrashort THz pulses.